This invention relates to flat woven electrical transmission cables having a plurality of conductors and more particularly to flat woven cable made of fine wire and thread, and designed to deliver matched or controlled impedance.
Flat woven impedance cable is indispensable for a number of applications. For example, such cable, which includes a pair of longitudinal ground wires carried between adjacent conductor wires in a substantially parallel relationship with the conductor wires, is disclosed in the U.S. Pat. No. 4,143,236 of Ross et al. Such cables have reduced cross-talk interference and a controlled impedance providing uniform signal propagation.
However, an increased demand for size reductions in such cable has led to a high incidence of mechanical failure. For example, such failure or breakdown frequently occurs in those areas where these cables are handled, installed and/or flexed in use: (1) at the outside edges where the solid copper conductors are subjected to unsustainable angular forces; (2) at the terminal connector end where the conductors must flex while at the same time sustaining a pulling force; and (3) at any place in the cable where the cable must be bent through a small radius from 90.degree. to 180.degree. and then back to its original position.
Efforts to correct the problems at the connector end have included potted and epoxy-filled backshells and clamping pressure from molded backshells. In addition, a variety of jacket designs has been used in an attempt to overcome the problems. However, improved connectors will not prevent breakdowns which are caused by the cable being bent through a small radius and then back to its original position and may not fully protect the cable from other types of failure.